The field of the disclosure relates generally to gas turbine engines and, more particularly, to a center frame construction and a joint assembly in a gas turbine engine.
Gas turbine engines are known to include an annular turbine center frame and a flowpath liner to protect the frame and its casing from hot gases passing through the frame. The flowpath liner is exposed to the hot engine gases and thus expands and contracts in the circumferential direction about the annular frame at a higher magnitude than the engine casing to which it is attached, since the liner shields the casing from direct exposure to the same high temperature gases. Due to the significance of expansion and contraction of the liner, the liner is typically segmented so that individual segments are exposed to smaller fractions of the overall thermal expansion phenomenon. To sufficiently shield the casing from high temperature gases, the individual segments of the flowpath liner must contact each other and overlap one another where adjacent segments meet.
The continual expansion and contraction of individual flowpath liner segments causes wear along the edges where individual segments meet and slide against one another. It has been known in some cases to provide a wear-resistant coating along individual segment edges that slide against one another, in order to mitigate the amount of wear seen by individual edges over time. This conventional practice though, only protects against component wear in the two dimensional, circumferential direction of thermal expansion/contraction. As the wear-resistant coating thins over time, often due to friction between the sliding edges, joints holding individual overlapping segments against one another experience some play between the overlapping segments in the direction perpendicular to the circumferential direction. Over time, this play between segments can result in rattling, or “chatter”, in the perpendicular direction, thereby leading to structural damage to not only the overlapping segments, but also to the joints themselves.